1. Field of the Invention
This invention relates generally to apparatus employing a surge protector and, more particularly, to an electrical distribution panel, such as a residential loadcenter, including a surge protector device.
2. Background Information
Loadcenters are electrical distribution devices used in residential, industrial and commercial applications. Electrical distribution loadcenters typically comprise a wall mounted box enclosure. Within the enclosure is mounted an interior panel which supports conductive bus bars and electric circuit breakers attached to the interior and to the bus bars. A dead front cover is disposed over the box with openings for the circuit breaker handles to project therethrough. A door is hinged to the enclosure over the dead front to conceal the circuit breaker handles. Examples of loadcenters are disclosed in U.S. Pat. Nos. 5,280,132; and 5,337,211.
Loadcenter enclosure boxes may be provided in various lengths according to the number of circuits to be provided therein. Therefore, each loadcenter having a different capacity employs its own enclosure box, or, alternatively, a single enclosure box large enough to accommodate a wide range of circuit capacities may be used.
A loadcenter may be used as service entrance equipment, in which case the enclosure becomes a part of an electrically grounded system, or it may be used as a sub-fed device (i.e., in a multiple unit dwelling) wherein the box is not required to be a part of the electrical grounding system.
U.S. Pat. No. 5,053,919 discloses adding xe2x80x9cplug inxe2x80x9d surge protective devices in loadcenters, in which a circuit breaker is combined with a surge protector.
U.S. Pat. No. 5,136,460 discloses a whole house surge protector unit in an insulating housing external to a loadcenter for protection of a plurality of circuit branches.
U.S. Pat. No. 5,204,800 discloses a voltage or power surge suppression device having a circuit breaker/interrupter format or a format which is interfaceable with power panels or panelboards. The device includes normal and/or failed indication diagnostics, such as a light emitting diode (LED) and/or audible means. The LED is visible through an opening in a top wall of the isolation device in one of the circuit breaker positions.
U.S. Pat. No. 5,303,116 discloses a surge protector for AC power lines having components mounted on a circuit board.
U.S. Pat. No. 5,627,720 discloses a three-phase power distribution box including built in surge suppression capabilities. A socket is designed to accept a surge suppression module that can be removed and replaced while the electrical connections are hot.
U.S. Pat. No. 6,034,611 discloses a panelboard suitable for residential, commercial or industrial uses. The panelboard includes a dual-pole isolation device for electrically isolating arcing faults. The isolation device includes xe2x80x9cplug-inxe2x80x9d surge protection circuitry (see U.S. Pat. No. 5,412,526) to protect two distribution buses from voltage surges. The surge protection circuitry includes a light emitting diode (LED) within the enclosure which emits a signal to indicate that the surge protection circuitry is operational. Otherwise, when the LED is extinguished entirely, replacement of the surge protection circuitry is indicated.
Copending, commonly assigned U.S. patent application Ser. No. 09/536,330 discloses a surge protected electrical power distribution system in which the first ends of electrical power buses of a surge protector unit are secured to corresponding buses of a main disconnect unit, and the second ends of the surge protector unit""s buses are connected to buses of a multiple meter unit.
Copending, commonly assigned U.S. patent application Ser. No. 09/504,992 discloses a commercial or industrial panelboard including an enclosure that houses circuit breakers for electrical connection between a plurality of power lines and a plurality of loads. A second external enclosure is provided for a surge protection device. Wires or suitable conductors are provided to electrically connect power line legs and neutral (and/or ground) from the panelboard to the surge protection device. Alternatively, the second enclosure may be housed within the first enclosure.
Many manufacturers market surge protection devices for residential users. Various known devices and arrangements protect loads from surges in power supply voltage. Generally, both series and parallel protection are employed. Typically, if surge protection is desired, then customers (e.g., individuals; owners of buildings having multiple tenants, such as offices or apartments) purchase separate surge protection devices and wire those surge protection devices into the electrical power distribution system themselves. Alternatively, individuals may employ surge protection devices (e.g., outlet plug-ins; strips) at selected power outlets.
There is room for improvement in electrical distribution panels and surge protection therefor.
This and other needs are met by the present invention in which an electrical distribution panel comprises an enclosure having a window and at least one opening associated with at least one electrical switching device; and a surge protector device including at least one indicator, which is visible through the window of the enclosure. In this manner, a user may readily observe the health of the surge protector device, without employing an electrical switching device opening of the enclosure for the surge protector device. Alternatively, one or more electrical switching devices may be dedicated to provide short circuit protection for the surge protector device.
As one aspect of the invention, an electrical distribution panel houses at least one electrical switching device each of which is adapted for electrically interconnecting at least one power line with at least one load. The electrical distribution panel comprises: an enclosure including a window and at least one opening; at least one input adapted for electrical connection to the at least one power line; means for housing at least one electrical switching device in association with a corresponding at least one of the at least one opening of the enclosure; and a surge protector device electrically interconnected with the at least one input for protecting the at least one load from surges or transients on the at least one power line, the surge protector device including at least one indicator which is visible through the window of the enclosure.
Preferably, the surge protector device includes an enunciator for indicating a status condition of the surge protector device. The enunciator may include an audible alarm for enunciating an occurrence of a surge or transient event on the at least one power line. The enunciator may include a circuit breaker electrically connected to one of the inputs for electrical connection to one of the power lines for supplying power to the enunciator.
As another refinement, the at least one power line includes a first power line leg and a second power line leg, and the surge protector device includes a first input for the first power line leg and a second input for the second power line leg. The surge protector device may include a two-pole circuit breaker having a first pole and a second pole, with the first input of the surge protector device including the first pole and the second input of the surge protector device including the second pole, and with the first and second poles being electrically interconnected with the first and second power line legs, respectively.
Preferably, the enclosure includes a door, which selectively covers the window and the at least one opening of the enclosure.
As another aspect of the invention, a residential loadcenter houses a plurality of circuit breakers each of which is adapted for electrically interconnecting at least one power line with at least one load. The loadcenter comprises: an enclosure including a window and a plurality of openings; at least one input adapted for electrical connection to the at least one power line; means for housing a plurality of the circuit breakers in association with corresponding ones of the openings of the enclosure; and a surge protector device mounted within the enclosure and apart from the means for housing, with the surge protector device electrically interconnected with the at least one input for protecting the loads from surges or transients on the at least one power line, the surge protector device including at least one indicator which is visible through the window of the enclosure.